mirror whole hard disk with rsync

[Marc Perkel]

Clint Byrum wrote:

>On Thu, 2004-02-19 at 07:48, Marc Perkel wrote:
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>>Dick - that doesn't answer the man's question.
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>Its a valid question though (asking why not use RAID1 I mean). If we
>knew that, we could better serve his rsync question. Or he might not
>have realized that for things like this, RAID1 might be better. It just
>depends on his goals.
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>For instance, if you're using removable IDE disks and rotating them
>periodically... RAID1 will not be good, because you'll have to re-sync
>the whole RAID1 every time.
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>Then again, in situations like those.. something like drbd(distributed
>redundant block device) comes to mind. Google for drbd... network RAID1
>done right basically.
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The reason I don't user Raid 1 is that more often than not I'm fixing 
things for a bad install or accidental deletion. My second drive is my 
UNDO drive. If I screw up using raid - i screw up both drives.

>>mount the other drive say as "/backup"
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>>rsync -ax --delete --force / /backup/
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>Almost.. you made the same mistake I made a few months ago when doing
>this.
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>rsync -ax --delete --force --exclude /backup / /backup/
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>Otherwise.. every time you do this, you end up copying your backup to
>/backup twice. ;)
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Actually - doesn't the -x mean to not cross file systems and makes it 
not backup the backup directory?

>>I think that will do it.
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>>You might want to run a list of rsync commands on a list of directories 
>>if you are coppying a lot of files. I do the same thing where I back up 
>>critical files with one script hourly - other user files nughtly - and 
>>the system stuff manually after installing new software. I like doing it 
>>this way rather than raid 1 becaue if I screw up I can use rsync to undo it.
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>Right, thats why RAID1 is for redundancy, and rsync is for backups. ;)
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